docs: def on_channel_open(self, channel):
          """This method is invoked by pika when the channel has been opened.
          The channel object is passed in so we can make use of it.
  
          :param pika.channel.Channel channel: The channel object
  
          """
          LOGGER.debug('Channel opened')
          self.channel = channel
          if self.publisher_confirmations:
              self.channel.confirm_delivery(self.on_delivery_confirmation)
          self.channel.add_on_close_callback(self.on_channel_closed)
          self.channel.add_on_flow_callback(self.on_channel_flow)
          self.channel.add_on_return_callback(self.on_basic_return)
          self.state = self.STATE_READY
          if self.on_ready:
              self.on_ready(self)